“Eat your fruits and vegetables” is one of the first nutritional lessons we learn, probably around age 2. And while it’s good advice for the rest of our lives as well, even nutritionists have generally underestimated the power of a mostly-vegetable diet. The Telegraph reports a recent presentation from Harvard researchers indicates a vegetarian diet is even more beneficial than previously thought, affecting not just people’s weight but their overall health.

“That’s not even talking about physical activity or not smoking, and that’s all deaths, not just cancer deaths,” said Walter Willett, a professor of epidemiology and nutrition at Harvard Medical School.

He says 200,000 lives could be saved in the U.K. annually just by cutting out meat in favor of a plant-based diet. David Jenkins, the scientist who developed the idea of the “glycemic index” for carbohydrates, was also at the conference, and he added the benefits of a vegetarian diet have been “undersold.” Rather than following a paleo diet, he suggests people opt for a “simian diet” similar to what gorillas eat: leaves, veggies, stems, fruits.

More conference attendees jumped on the vegetarian bandwagon: “I think people imagine that a healthy diet has only a modest effect and a vegetarian diet might help you lose a little bit of weight,” said Neal Barnard, president of the Physicians Committee for Responsible Medicine. “But when these diets are properly constructed I think they are enormously powerful.”